Telephone-transmitter.



No. 811,098. PATENTED JAN. 30, 1906. M. SETTER.

TELEPHONE TRANSMITTER. APPLICATION FILED DEG.30,19047 2 SHEETS-SHBET 1.

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'PATENTED JAN. 30, 1906.

M. SBTTER. TELEPHONE TRANSMITTER.

APPLICATION FILED DEG.30,1904.

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MICHAEL SETTER, OF CHICAGO, ILLINOIS, ASSIGNOR TO AMERICAN ELECTRIC TELEPHONE COMPANY, OF CHICAGO, ILLINOIS, A COR- PORATION.

TELEPHONE-TRANSITTERu Specification of Letters Patent.

Patented Jan. 30, 1906.

Application filed December 30,1904. Serial No 238,902.

. To aZZ whom it may concern:

Be it known that I, MIoHAEL SETTER, a citizen of the United States of America, and

Ya resident ofChioago, Cook county, Illinois,

plified and efficient character, and in a trans- I mitter characterized by the principles of my invention the mouthpiece and casing are connected by means of a front plate composed of two sheet-metal parts, said parts being pressed into the proper shape and rigidly secured together by pressing or reaming over the edge portion of one part upon the other, and with a construction and arrangement of this character it is obvious that the transmitter is made lighter and. fully as strong and reliable as was heretofore possible and much cheaper and more economical to manufacture.

In the accompanying drawings, Figure 1 is a partial section of a telephone-transmitter embodying the principles of my invention. Fig. 2 is a front view of the front plate of the transmitter. Fig. 3 is an edge view of the said front plate of the transmitter. Fig. 4 is a top view of the said front plate of the transmitter. Fig. 5 is an enlarged section of said improved front plate of the transmitter; and Fig. 6 is a view similar to Fig. 5, but showing the two parts of the front plate separated and i in readiness to be secured together.

As thus illustrated, the transmitter, with the exception of the front plate, may be of any suitable, known, or approved construction. For example, it may comprise a diaphragm A, having its margin provided with a rubber band a. The usual mouthpiece B serves to direct the voice-vibrations against the said diaphragm, and a microphone or resistance-varying device C of any suitable character serves to convert the said vibrations into the desired current fluctuations in the line-circuit. A bridge D is provided and connected with said. microphone or resistancevarying device in any suitable or desired manner. The casing or back E of the transmitter can be of any suitable design and serves to inclose the internal parts of the transmitter. The front plate F of the transmitter is, however, of a highly-improved character. In order that the said front plate may be of a light and yet strong character, it is preferably composed of a couple of sheetmetal parts f and f It will be observed'that the sheet-metal part 7 is formed with a centrally and internally threaded boss or neck f adapted to receive the threaded end of the mouthpiece B. At its perimeter and before the two parts are secured together the said sheet-metal part 7 is provided with a cylindric flangef as shown in Fig. 6, and it is also provided, as shown, with a shoulder f On the other hand, the sheet-metal part f is preferably formed with a hollow box-like portion f, the same having radially and inwardly projecting flanges f 6 and a peripheral bead or relatively narrow flange f With this construction and formation of the two sheetmetal plates of which the front plate of the transmitter is composed it is evident that the two parts may be placed in engagement with each other and that the flangef can then be pressed or reamed over for the purpose of securing the two sheet-metal parts together, as shown more clearly in Fig. 5 When this has been accomplished, it will be seen that a front plate is provided having a shoulder or seat against which the marginal portions of the diaphragm A may rest, said shoulder or seat being provided by the flange f Furthermore, the fastening of the two sheet-metal parts together in this manner provides the front plate as a whole with a shoulder f against which the edge of the casing E may bear, it being understood that the said casing is adapted to fit upon the cylindric portion f of the said front plate, this portion of the front plate being provided by the box-like or hollow portion f of the sheet-metal part f. The flat inner surface f of the said. front plate can be provided with holes, as shown in Fig. 4, the same being adapted to receive the screws d, by which the said bridge D is firmly and properly secured in place to the said front plate. Thus constructed and, employed as the front of the transmitter the said front plate is very light, but at the same time strong and rigid, and in addition the said front plate is cheaply and economically manufactured, as it requires but the simplest and most economical operations during the process of its manufacture. In making it only sheet metal is employed, and the desired formation is obtained readily by simply pressing the two sheet-metal parts into the desired shapes. The threading of the boss or neck into which the mouthpiece is screwed is practically the only machine-work of this or any other similar character that is necessary.

What I claim as my invention is 1. A telephone-transmitter comprising a front plate composed of two sheet-metal parts pressed into the desired shapesand rigidly secured to ether, one of said parts having an interna ly-threaded boss, a mouthpiece screwed into said boss, a diaphragm having its marginal portions resting against the other sheet-metal part, a bridge suitably secured to the sheet-metal part on which the diaphragm rests, a casing fitted upon the periphery of the sheet-metal part to which the bridge is secured, and a microphone device connecting said diaphragm to said bridge.

2. A telephone-transmitter comprising a front plate composed of two sheet metal parts, one of said parts being pressed into such shape as to provide it with a hollow annular portion and a radially and inwardly projecting flange, and also with a peripheral bead or relatively narrow flange, and the other sheet-metal part being provided centrally with an internally-threaded boss and a peripheral flange pressed or reamed down upon the said bead or narrow flange of the other part; a mouthpiece screwed into said threaded boss, a diaphragm resting against the shoulder or seat provided by said inwardly-projecting flange, a bridge secured to said hollow annular portion, a microphone device connecting said diaphragm with the said bridge, and a casing fitted upon the said hollow annular portion of the front plate and bearing against the shoulder provided by the said pressed or reamed front portion of the front plate.

Signed by me at Chicago, Illinois, this 14th day of November, 1904. l

MICHAEL SETTER. Witnesses:

Jos. E. CONWAY, CLARENCE M. THORNE. 

